/* * Annapurna Labs MSIX support services * * Copyright (C) 2016, Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Antoine Tenart <antoine.tenart@free-electrons.com> * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/irqchip.h> #include <linux/irqchip/arm-gic.h> #include <linux/msi.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_pci.h> #include <linux/pci.h> #include <linux/slab.h> #include <asm/irq.h> #include <asm/msi.h> /* MSIX message address format: local GIC target */ #define ALPINE_MSIX_SPI_TARGET_CLUSTER0 BIT(16) struct alpine_msix_data { spinlock_t msi_map_lock; phys_addr_t addr; u32 spi_first; /* The SGI number that MSIs start */ u32 num_spis; /* The number of SGIs for MSIs */ unsigned long *msi_map; }; static void alpine_msix_mask_msi_irq(struct irq_data *d) { pci_msi_mask_irq(d); irq_chip_mask_parent(d); } static void alpine_msix_unmask_msi_irq(struct irq_data *d) { pci_msi_unmask_irq(d); irq_chip_unmask_parent(d); } static struct irq_chip alpine_msix_irq_chip = { .name = "MSIx", .irq_mask = alpine_msix_mask_msi_irq, .irq_unmask = alpine_msix_unmask_msi_irq, .irq_eoi = irq_chip_eoi_parent, .irq_set_affinity = irq_chip_set_affinity_parent, }; static int alpine_msix_allocate_sgi(struct alpine_msix_data *priv, int num_req) { int first; spin_lock(&priv->msi_map_lock); first = bitmap_find_next_zero_area(priv->msi_map, priv->num_spis, 0, num_req, 0); if (first >= priv->num_spis) { spin_unlock(&priv->msi_map_lock); return -ENOSPC; } bitmap_set(priv->msi_map, first, num_req); spin_unlock(&priv->msi_map_lock); return priv->spi_first + first; } static void alpine_msix_free_sgi(struct alpine_msix_data *priv, unsigned sgi, int num_req) { int first = sgi - priv->spi_first; spin_lock(&priv->msi_map_lock); bitmap_clear(priv->msi_map, first, num_req); spin_unlock(&priv->msi_map_lock); } static void alpine_msix_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) { struct alpine_msix_data *priv = irq_data_get_irq_chip_data(data); phys_addr_t msg_addr = priv->addr; msg_addr |= (data->hwirq << 3); msg->address_hi = upper_32_bits(msg_addr); msg->address_lo = lower_32_bits(msg_addr); msg->data = 0; } static struct msi_domain_info alpine_msix_domain_info = { .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_PCI_MSIX, .chip = &alpine_msix_irq_chip, }; static struct irq_chip middle_irq_chip = { .name = "alpine_msix_middle", .irq_mask = irq_chip_mask_parent, .irq_unmask = irq_chip_unmask_parent, .irq_eoi = irq_chip_eoi_parent, .irq_set_affinity = irq_chip_set_affinity_parent, .irq_compose_msi_msg = alpine_msix_compose_msi_msg, }; static int alpine_msix_gic_domain_alloc(struct irq_domain *domain, unsigned int virq, int sgi) { struct irq_fwspec fwspec; struct irq_data *d; int ret; if (!is_of_node(domain->parent->fwnode)) return -EINVAL; fwspec.fwnode = domain->parent->fwnode; fwspec.param_count = 3; fwspec.param[0] = 0; fwspec.param[1] = sgi; fwspec.param[2] = IRQ_TYPE_EDGE_RISING; ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec); if (ret) return ret; d = irq_domain_get_irq_data(domain->parent, virq); d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING); return 0; } static int alpine_msix_middle_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args) { struct alpine_msix_data *priv = domain->host_data; int sgi, err, i; sgi = alpine_msix_allocate_sgi(priv, nr_irqs); if (sgi < 0) return sgi; for (i = 0; i < nr_irqs; i++) { err = alpine_msix_gic_domain_alloc(domain, virq + i, sgi + i); if (err) goto err_sgi; irq_domain_set_hwirq_and_chip(domain, virq + i, sgi + i, &middle_irq_chip, priv); } return 0; err_sgi: while (--i >= 0) irq_domain_free_irqs_parent(domain, virq, i); alpine_msix_free_sgi(priv, sgi, nr_irqs); return err; } static void alpine_msix_middle_domain_free(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs) { struct irq_data *d = irq_domain_get_irq_data(domain, virq); struct alpine_msix_data *priv = irq_data_get_irq_chip_data(d); irq_domain_free_irqs_parent(domain, virq, nr_irqs); alpine_msix_free_sgi(priv, d->hwirq, nr_irqs); } static const struct irq_domain_ops alpine_msix_middle_domain_ops = { .alloc = alpine_msix_middle_domain_alloc, .free = alpine_msix_middle_domain_free, }; static int alpine_msix_init_domains(struct alpine_msix_data *priv, struct device_node *node) { struct irq_domain *middle_domain, *msi_domain, *gic_domain; struct device_node *gic_node; gic_node = of_irq_find_parent(node); if (!gic_node) { pr_err("Failed to find the GIC node\n"); return -ENODEV; } gic_domain = irq_find_host(gic_node); if (!gic_domain) { pr_err("Failed to find the GIC domain\n"); return -ENXIO; } middle_domain = irq_domain_add_tree(NULL, &alpine_msix_middle_domain_ops, priv); if (!middle_domain) { pr_err("Failed to create the MSIX middle domain\n"); return -ENOMEM; } middle_domain->parent = gic_domain; msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node), &alpine_msix_domain_info, middle_domain); if (!msi_domain) { pr_err("Failed to create MSI domain\n"); irq_domain_remove(middle_domain); return -ENOMEM; } return 0; } static int alpine_msix_init(struct device_node *node, struct device_node *parent) { struct alpine_msix_data *priv; struct resource res; int ret; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; spin_lock_init(&priv->msi_map_lock); ret = of_address_to_resource(node, 0, &res); if (ret) { pr_err("Failed to allocate resource\n"); goto err_priv; } /* * The 20 least significant bits of addr provide direct information * regarding the interrupt destination. * * To select the primary GIC as the target GIC, bits [18:17] must be set * to 0x0. In this case, bit 16 (SPI_TARGET_CLUSTER0) must be set. */ priv->addr = res.start & GENMASK_ULL(63,20); priv->addr |= ALPINE_MSIX_SPI_TARGET_CLUSTER0; if (of_property_read_u32(node, "al,msi-base-spi", &priv->spi_first)) { pr_err("Unable to parse MSI base\n"); ret = -EINVAL; goto err_priv; } if (of_property_read_u32(node, "al,msi-num-spis", &priv->num_spis)) { pr_err("Unable to parse MSI numbers\n"); ret = -EINVAL; goto err_priv; } priv->msi_map = kzalloc(sizeof(*priv->msi_map) * BITS_TO_LONGS(priv->num_spis), GFP_KERNEL); if (!priv->msi_map) { ret = -ENOMEM; goto err_priv; } pr_debug("Registering %d msixs, starting at %d\n", priv->num_spis, priv->spi_first); ret = alpine_msix_init_domains(priv, node); if (ret) goto err_map; return 0; err_map: kfree(priv->msi_map); err_priv: kfree(priv); return ret; } IRQCHIP_DECLARE(alpine_msix, "al,alpine-msix", alpine_msix_init);